1. Field of the Invention
The present invention relates to touch device technology, and in particular to a touch device and fabrication method thereof.
2. Description of the Related Art
Recently, touch devices have been popularly applied in various electronic products, such as mobile phones, personal digital assistants (PDA) and handheld personal computers. Currently, a design scheme has been developed in which the touch devices being manufactured are increasingly thin. The thin touch device includes a cover lens and touch-sensing elements, wherein the touch-sensing elements are directly formed on one side of the cover lens, and the other side of the cover lens is provided for users to be able to touch in order to input signals or control the electronic product. Therefore, the cover lens has both its original function of protection and a new function for carrying the touch-sensing elements. An original substrate of conventional touch devices for carrying the touch-sensing elements can be omitted. The thin touch devices have the advantages of being light in weight and having a thin profile, and thus these thin touch devices are gradually being favored by more and more consumers.
In the thin touch devices, firstly, a decorative layer is formed on the cover lens to define a peripheral area. Another area inside the peripheral area is usually defined as a viewable area. Then, a transparent electrode layer is formed on the cover lens to be used for a touch-sensing electrode. The transparent electrode layer extends from the viewable area to the peripheral area and over the decorative layer. Next, a signal-conveying trace is formed on the decorative layer to be in direct contact with the transparent electrode layer. Therefore, an electrical signal produced from the touch-sensing electrode is transmitted to an external detection circuit through the signal-conveying trace, and a touch-position is determined by the external detection circuit.
Because the decorative layer usually has a thickness of several micrometers (μm) to several tens of micrometers, the transparent electrode layer needs to straddle a step structure with a height of several micrometers (μm) to several tens of micrometers for extending from the viewable area to be on the decorative layer at the peripheral area. Thus, it is difficult to form the transparent electrode layer, and the step-covering ability of the transparent electrode layer on the decorative layer is reduced by an increase of the thickness of the decorative layer. It causes the transparent electrode layer to break easily, and the reliability of the electrical connection between the transparent electrode layer and the signal-conveying trace is thereby reduced.